Mount CIFS-share with users Kerberos-Ticket

Question

we want to mount shares through autofs. Nothing special we thought. But: this must be done in some complex active directory circumstances. What we have: integrated Ubuntu 14.04 workstations on which users can login with their windows credentials. The most work is done using sssd, which also creates an kerberos-ticket at login-time.

Now: we want to use this ticket to authenticate for network shares.

The complex circumstances are: the AD is based on many location nameconventions. Following configs are anonymized. THE PROBLEM:

The mounting attempt fails with:

cifs.upcall: find_krb5_cc: considering /tmp/krb5cc_594111_644IQv
cifs.upcall: find_krb5_cc: FILE:/tmp/krb5cc_594111_644IQv is valid ccache
cifs.upcall: handle_krb5_mech: getting service ticket for shareserver.sub.example.org
cifs.upcall: cifs_krb5_get_req: unable to get credentials for shareserver.sub.example.org
cifs.upcall: handle_krb5_mech: failed to obtain service ticket (-1765328377)
cifs.upcall: Unable to obtain service ticket

So the kerberos-ticket is for USERNAME@EXAMPLE.COM generated. But we want to connect to SHARESERVER.SUB.EXAMPLE.ORG

Is our kerberos ticket not valid to connect to the server or is this a misconfigured kerberos-system, which doesnt link from sub.example.com to example.com.

Krb5.conf:

[libdefaults]
    default_realm = EXAMPLE.COM
# The following krb5.conf variables are only for MIT Kerberos.
    krb4_config = /etc/krb.conf
    krb4_realms = /etc/krb.realms
    kdc_timesync = 1
    ccache_type = 4
    forwardable = true
    proxiable = true

 # The following libdefaults parameters are only for Heimdal Kerberos.
    v4_instance_resolve = false
    v4_name_convert = {
            host = {
                    rcmd = host
                    ftp = ftp
            }
            plain = {
                    something = something-else
            }
    }
    fcc-mit-ticketflags = true
 [realms]

 [domain_realm]
    .example.com = EXAMPLE.COM
    example.com = EXAMPLE.COM
 [login]
    krb4_convert = true
    krb4_get_tickets = false

Mount CIFS-share with users Kerberos-Ticket

0 Answers0